Photoprotection by dietary carotenoids: Concept, mechanisms, evidence and future development

Abstract

Carotenoids are micronutrients present mainly in fruits and vegetables, and they are ingested from these sources with the diet. They exhibit specific antioxidant activity but also influence signaling and gene expression at the cellular level. β-Carotene and lycopene, the colorants of carrots and tomatoes, respectively, are among the most prominent members of this group of lipids, and they are usually the dominating carotenoids in human blood and tissues. Both compounds modulate skin properties when ingested as supplements or as dietary products. There is evidence that they protect the skin against sunburn (solar erythema) by increasing the basal defense against UV light-mediated damage. Their photoprotective efficacy, however, is not comparable to the use of a sunscreen. In vitro data show that also other carotenoids are efficient photoprotectors. Among them are lutein and structurally unusual phenolic polyenes like 3,3'-dihydroxyisorenieratene.

New Developments in Lycopene Analysis by Spectroscopic and Chromatographic Techniques, Accompanied With Mathematical Modelling

“…These are also the conclusions of the recently published study by Terao et al [143]. There is much evidence that lycopene protects the skin against sunburn (solar erythema) by increasing the basal defense against UV light-mediated damage [144].…”

Cardiovascular benefits of lycopene: fantasy or reality?

“…Other mechanisms include prevention of oxidative damage (58,59) , inhibition of angiogenesis (59,60) , induction of phase II enzymes (61)(62)(63) , interaction with growth factors and sex hormones (64) and the induction of nuclear receptors activation (65)(66)(67) . Lycopene has also been found to confer photoprotection (68) . Interestingly, it has been recently shown that lycopene, via bioactive metabolites, possesses partial pro-vitamin A activity transmitted via retinoic acid receptor-mediated signalling in mice (69) .…”

Lutein – The Less Explored Carotenoid

“…The protection mechanisms involve both quenching of singlet oxygen and of damaging free radicals. Lutein [ 100,101] Nutri-cosmetics and cosmeceuticals available commercially as beauty pills or oral cosmetics are composed of antioxidants like lutein thus having antiaging effect. [102] Some in vitro studies have also proved the efficiency of lutein as photo protectors, they protect the skin against sunburn (solar erythema) by increasing the basal defence against UV light-mediated damage.…”